Contact-point bed.



I. HADLEY.

CONIACT POINT BED. APPLICATION FILED JULY 16. I917.

imww.

lmwemilobv mwaimy .4] WWW,

Patented Nov. 27, 1917.

conrncr-rorn'r Ben.

masses Specification of Letters Patent.

Patented New. 12?, Edit.

I Application filed July 16, 1917. Serial Ito. 180,960.

'To all whom it may concern:

Be it known that I, IRVING HADLEY, a citizen of the United'States,residing at Los Angeles, in the county of Los Angeles and .State ofCalifornia, have invented new and useful Improvements in Contact- PointBeds, of which the following is a specification.

This invention relates to a grinding block for contact points.

In the various ignition systems used in connection with internalcombustion engines, contact points are utilized to make and break thecircuits within the timer, or magneto. It is essential that these pointsstrike the contact plates squarely in order to prevent corrosion of thepoints and a weakened current. It is the principal object of thisinvention to provide a simple device for holding the contact pointswhile they are being ground so that the endv face of the points may besmoothed with precision, thus pro.

ducing the results desired.

Other objects will appear hereinafter.

The invention is illustrated, by way of example, in the accompanyingdrawings in which:

Figure 1 is a view in perspective illustrating the grinding bed andparticularly showing the contact point channel extending the lengththereof.

Fig. 2 is a view in transverse section through the grindingbeddisclosing one of the contact. members mounted therein.

Fig. 3 is a view in longitudinaf section as seen on the line 3--3 ofFig. 2 illustrat-.

ing the manner in which a spring contact member is held in the block.

Fig. 4 is a view in longitudinal section illustrating a contact screw asmounted for grinding within the block.

Fig. 5 is a perspective'vicw of one'of the shims used with the block.

Fig. 6 is a view in perspective illustrating the spring contact memberwhich is ground.

Fig. 7 is a view in perspective illustratingzone of the screw contactmembers.

. eferring more particularly to the drawin 10 indicates the grinding bedpreferabl? formed of a Hat piece of hardened steel, rectangular inshape. This bed has a groove 11 extending its lengthv and provided toreceivethe leaves 12 and 13 of the spring contact member 14. The sidewalls of the groove are formed with two inclined faces 5 undid-formingan intermediate shoulder 17 upon which the upper lea-i 12 rests duringthe grinding operation, as particularl shown in Fig. 2. Formed upondiametrically opposite sides of the groove are threaded openings 18 and1.9 which extend through the bed and may be used for two purposes. Whenthe spring contact members 14 are being ground, these openings mayreceive a clamping screw 20 by which a series of shim plates 21 aresecured. This screw passes through openings 22 in the shim plate, whileopenings 23 are provided to receive the contact point 2% of the member.it. in the other instance, a contact screw 25 is ground by passing itthrough one of the openings 18 and 19 and allowing it to pro jectslightly above the face of the bed. When the device is used in grindingthe spring contact members, the member is inserted into one end of thegroove 11, care being taken to place the leaf 12 above the shoulder 17in the-groove and the lower leaf 13 in the groove portion therebeneath.A

suficient number of shim plates are then placed over the bed and theiropenings 23 rought to register with the contact point 24.. When enoughof the plates have been placed over the point to allow it to barelyextend above the surface of the top plate,

the clamping screw 20 is placed through the openings 22 and drawn tightagainst the face of the bed. As the shim plates are hardened steel, theassembled block may then be placed face downward upon a Whetstone andrubbed thereover until the contact point is flush with the face of theouter shim.

This will insure a square smooth surface upon the end of the point. Ingrinding the screw contacts 25 the screw is inserted into one of theopenings 18 and 19 and tightened down until it iprojects slightly abovethe opposite face 0 the plate. It may then be whetted as desired.

It will thus be seen that the grinding block hereprovided is simple inits construction andwill allow the contacts to be ground with precision.

While I have shown the preferred form of my contact point bed as nowknown to me, it is evident that various changes in the combination,construction and arrangement of parts may be made by those skilled inthe art without departing from the spirit of my invention.

ll claim:

l. A grinding bed, comprising a solid bed.

portion, aslot extending lengthwise thereof for the'reception of contactpoints to the ground, and means for holding the face of the pointssquare with the face of the bed during the grinding operation.

2. A grinding bed, comprising a solid bed ortion, a slot extendinglengthwise thereof or the reception of contact points to the ground,means for holding the face of t 2- points square With the face of thebed during the grinding operation, and means for positively determiningand limiting the depth of metal'to be ground from the ends of thepoints.

3. A. grinding bed for contact points, comprising a hardened steel bedplate having a longitudinal slot extending the length of one facethereof, threaded openings positioned through the bed plate at oppositesides of the slot and at'right angles to the faces of the plate, andhardened steel shim plates adapted to be secured upon the face of thebed plate in a manner to protect the point of the contact memberextending from the slot or through one of the threaded openings.

'In testimony whereof I have signed my name to this specification.

' IRVING HADLEY

